【摘要】 近年来的观测结果显示北极对流层臭氧发生亏损的同时 ,大气中的气态汞浓度也急剧下降。这种现象的发生被认为是大气中活性卤素物种的增多而引起的。活性的卤素物种例如Br/Cl与臭氧作用 ,一方面导致臭氧亏损 ,同时 ,生成BrO/ClO氧化大气中的Hg0 ,使Hg0 转化为活性汞 (RGM)而沉降。北极地区大气中活性卤素物种主要来自海洋大型藻类释放的卤代烃分解和海盐的贡献。在过去的几十年里 ,随气候变暖 ,北极海冰变薄 ,面积减少 ,海洋排放的活性卤素物种浓度增加 ,从而使北极地区大气中的汞沉降通量增加 ,加剧了北极生物圈中的汞污染。由于北极海冰减少变薄趋势还在持续 ,因此 ,北极大气中汞亏损引起的沉降通量增加对生态圈的影响应该引起广泛重视。本文在综述这方面研究的最新进展基础上 ,提出了今后的研究方向。更多还原

【Abstract】 The recent monitoring results suggest that the level of gaseous mercury abruptly decreases corresponding to the depletion of ozone in the Arctic troposphere. This abnormal phenomenon is ascribed to the increase of reactive halogen species (RHS) in the atmosphere. RHS like Br/Cl interacts with ozone resulting in the depletion of ozone and production of BrO/ClO, which converts gaseous Hg 0 to reactive gaseous mercury (RGM) and deposition from the atmosphere. The source of RHS mainly comes from the photochemical degradation of volatile halogenated organic compounds (VHOC) emission from marine macroalgae and inorganic halogen species from sea salts. During the several decades, the RHS level enhances and the rate of deposition of mercury increases since the Arctic sea ice becomes thinner and the area diminishes in responding to warming up. This process hence strengthens mercury contamination in the Arctic ecosystem. Due to the trend of decrease of the Arctic sea ice, the role of depletion of mercury in the atmosphere influences on the Arctic ecosystem should be received broad attention. Here we summary the progress of research related to this topic and propose possible research plane in the near future.更多还原